Math - Ratios

2:1: 2 carrot to 1 tomato.
1:3: 1 bread to 3 onigiri.

The ratio is the relation between two values.

Part-to-Part & Part-to-Whole

A ratio has two types of relationships:

• Part-to-Part: The relationship between one part and another part.

  10:14: 10 red to 14 blue.
  14:10: 14 blue to 10 red.

• Part-to-Whole: The relationship between one part and the whole, the total.

  10:24: 10 red to 24 total.
  14:24: 14 blue to 24 total.

Equivalent Ratios

Ratios are equivalent if they have the same proportion.

Examples

$9:57 = 3:19\\ 18:27 = 2:3\\ 12:24 = 1:2$

Scaling Ratios

Ratios represent a proportion that can be increased or decreased.

• 2:4
  • 1:2
  • 4:8

• 8:6
  • 4:3
  • 12:9